MKV to MP4 Batch Converter (GUI)

A simple cross-platform Python GUI for batch converting .mkv files to .mp4 using FFmpeg.

• Fast remux (no quality loss) if video = H.264 and audio = AAC/AC3/E-AC3/MP3/MP2
• Automatic transcode (H.264/AAC) if streams are not MP4-friendly
• Converts SubRip subtitles (.srt) to MP4-compatible mov_text
• Preserves chapters & metadata
• Built with Tkinter → works on Windows, macOS, and Linux

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📦 Requirements

• Python 3.8+
• FFmpeg (must be on your system PATH)
  • ffmpeg
  • ffprobe

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🔧 Installing FFmpeg

Windows

1. Download a static build from gyan.dev FFmpeg builds.
2. Extract the archive (e.g. C:\ffmpeg).
3. Add the bin folder to your PATH:
   • Press Win+R, type sysdm.cpl, go to Advanced → Environment Variables.
   • Under System variables, edit Path, add:

     C:\ffmpeg\bin
     

   • Click OK, then restart your terminal.
4. Test by running:

   ffmpeg -version
   ffprobe -version

macOS

• Install via Homebrew:

  brew install ffmpeg

• Or download a static build from evermeet.cx.

Linux (Debian/Ubuntu)

sudo apt update
sudo apt install ffmpeg

Most modern distros already have FFmpeg in their repositories.

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🚀 Usage

1. Clone this repo:

   git clone https://github.com/ryanxedi/mkv2mp4.git
   cd mkv2mp4

2. Run the app:

   python mkv2mp4_gui.py

3. In the GUI:

   • Click Browse… and select a folder containing .mkv files.
   • Choose options:
     • Include subtitles (SRT → mov_text)
     • Keep all audio tracks
     • Overwrite existing MP4 files
   • Decide what to do with non-compatible files:
     • Ask (prompt per file)
     • Transcode (convert automatically)
     • Skip

4. Hit Run and watch the log as each file is processed.

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⚡ Fast vs Transcode Mode

• Fast Remux → No re-encoding. Instant. No quality loss.
• Transcode → Needed only if video isn’t H.264 or audio isn’t MP4-friendly.
  • Video → re-encoded with H.264 (libx264, CRF 18, preset slow)
  • Audio → re-encoded with AAC (256k)

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📝 Notes

• External MKV attachments (fonts, images) are not copied into MP4.
• Non-SRT subtitle formats are skipped unless re-encoded separately.
• MP4 with mov_text subs doesn’t support advanced styling — if you need formatting, export as .srt instead.

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🖥️ Compatibility

• ✅ Windows 10/11
• ✅ macOS (Intel & Apple Silicon)
• ✅ Linux (Ubuntu, Debian, Fedora, Arch, etc.)

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📄 License

MIT License.